Cathode ray tube supporting device



. p 1958 J. J. WlELENGA 2,852,768

CATHODE RAY TUBE SUPPORTING DEVICE Filed March 1, 1955 NM NM AM M! vnunmnnnlllwl INVENTOR. JENNO JOHANNES WIELENGA Fig. 4 BY Agent United States Pm m Ice CATHODE RAY TUBE SUPPORTING DEVICE Jenno Johannes Wielenga, Emmasingel, Eindhoven, Netherlands, assignor, by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application March 1, 1955, Serial No. 491,385

Claims priority, application Netherlands March 6, 1954 Claims. (Cl. 340367) The invention relates to a television apparatus comprising a cathode-ray tube, more particularly a tube having a metal cone and a rectangular image screen.

When mounting large cathode-ray tubes, having for example a (maximum) image screen diameter of 21", in the cabinet of a television receiver, difficulties are experienced, since such large tubes can, as a rule, not be manufactured with small tolerances with respect to the dimensions of the screen; this applies, more particularly to tubes having a metal cone and a rectangular screen.

Since the said tolerances may be 5 to mms. it is, for example, not possible without special measures to fix the position of the screen in the cabinet of the apparatus by means of a positioning member, for example an upright holding edge or rim surrounding narrowly the screen, since if the tube is to be replaced by a new one, the edge thereof might be found not to fit into the holding edge.

According to the invention this difficulty is obviated by providing on the conical partof the tube, near the edge of the image screen, a rigid frame which surrounds the tube and which, in turn, is surrounded by a supporting member secured to the cabinet of the apparatus and supporting the frame. The supporting member is preferably constituted by an upright edge or rim of insulating material, embracing narrowly the frame and secured to the front wall of the apparatus.

In order that the invention may be readily carried into effect, it will now be described more fully with reference to the accompanying drawing, in which:

Fig. 1 is a rear view of an embodiment of a portion of a television receiver which is essential for the inventron;

Fig. 2 is a sectional view taken on the line II--II of Fig. 1;

Fig. 3 is a modification of the embodiment of Fig. 2, in section; and

Fig. 4 is another modification of the embodiment of Fig. 2, in section.

Fig. 1 shows a television receiver comprising a cathoderay tube 1 having a rectangular image screen, the tube being accommodated in a cabinet 3, for example of wood. From Fig. 2, which shows a portion of the device shown in Fig. 1 near one of the rounded angles of the image screen 5 of the tube 1 in an axial view, it is evident that the image screen 5 is arranged behind a viewing hole 7 in the front of the cabinet 3. The image screen 5 is framed by a so-called mask 9 of insulating material, the sectional area of which is channel-shaped and which is secured to the front wall 3. The mask 9 hides the edge of the metal cone 11 of the tube 1, said edge surrounding the image screen 5, and at the same time insulates the said edge from the cabinet 3. Between the mask 9 and the wall 3, in a groove along the edge of the viewing hole 7, provision may be made of a glass guard 13.

As stated before, the dimensions and the shape of the image screen 5 are subjected to comparatively large tolerances and it is not possible to construct the mask 9 in a manner such that, for example, its upright outer 2,852,768 Patented .Sep t-Q 16, "1958 2 edge 15 fits intimately around the edge of the image screen 5. In order to ensure that the screen 5 is always in its correct position relative to the 'viewing 1hole7, the conical part of the tube 1 is surrounded, :in' the proximity of the edge of the image screen 5, preferably at a distance therefrom of not more than A of the axial length of the conical part of the tube 1, by a rigid frame 17 of metal or insulating material. The frame 17 bears preferably (see Fig. 1) on the metal cone 11 of the tube only near the rounded angles of the image screen, i. e. at the parts of the greatest mechanical rigidity. In the case concerned, the frame 17 is embraced by and secured to the upright edge 15 of the mask 9, the inner side of said edge constituting a cylindrical surface, the axis of which is at right angles to the front wall 3. By means of fastening bolts 19, provided with a hook and engaging the edge of the image screen, the frame 17 is secured to the cone 11 and the structure is secured so as'to be displaceable to the edge 15 by means of fastening bolts 21. The bolts 21 are introduced through two large holes in the edge 15 and are screwed into one or more edge parts of the frame 17 bent at right angles.

Since the frame 17 may be manufactured with comparatively accurate dimensions, the fastening described above ensures that the cathode-ray tube, the tolerances of the size of the image screen, always occupies its correct position in the cabinet, even when the tube is exchanged. It is a further advantage that the tube is primarily supported by a member engaging the comparatively rigid metal cone 11, while the vulnerable seal of the glass screen to the metal cone is exposed only to a low mechanical load.

The mask 9, the frame 17 and the glass guard 13 constitute a dust-tight envelope for the screen 5. In order to render the connection of the frame 17 to the cone 11 also dust-tight, the cone is preferably surrounded between said frame and the screen 5 by a closed, elastic rope or tube 23, for example of rubber, which engages the said frame and said cone under tensile force and which provides a dust-tight closure between the said frame and the said cone.

In the modification shown in Fig- 3, the frame 17 is adjustable relative to the mask 9 by means of set screws 25, and the tube 1 with the frame 17 is urged between the set screws 25 screwed into the frame, for example, by a slightly resilient strap 27, secured to the cabinet 1, in :an axial direction against the mask 9.

Fig. 4 shows another modification, in which the frame 17 is secured by means of screw bolts 29, engaging the front wall of the cabinet, in this case, the mask 9. The image screen 5 of the tube bears on the inner edge 31 of the mask 9, which edge may be provided with an elastic fillet 33, providing a dust-tight closure.

While the invention has been described by means of specific examples and in specific embodiments, I do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. A supporting device for mounting a cathode-ray tube having a metal cone and a substantially rectangular image screen in a cabinet, comprising a rigid frame secured to said metal cone, a mask of insulating material secured to said cabinet, means fixing said frame to said mask, and means co-acting with said frame and mask for adjusting the position of said tube and said frame in the direction of the longitudinal axis of the tube.

2. A supporting device as set forth in claim 1, further comprising fastening means for securing said rigid frame to an edge of said image screen.

3. A supporting device as set forth in claim 2, further comprising fastening means which secures the rigid frame 5. A supporting device for mounting a cathode-ray tube to the front wall of said cabinet. t as set forth in claim 1, wherein said rigid frame engages 4. A supporting device as set forth in claim 1 further said tube only at the area of the rounded corners of the comprising elastic material positioned between the frame image screen.

and the tube, said elastic material engaging said irame 5 under a tensile force to thereby provide a substantially dust-tight closure formed by the inner contiguous sur- UNITED STATES PATENTS faces of the frame, mask and tube. 2,684,477 Fisch July 20, 1954 References Cited in the file of this patent 

